Vacuum tube



Feb. 1, 1927.el J. L BROWN VACUUM TUBE Filed May 5, 1922 Lalli/fwd UNITED STATES.

PATENT OFFICE.

JOHN' L. BROWN, OF LONG BEACH, CALIFORNIA.

vacuum TUBE.'

Application med Bay 5,

This invention relates to electrical ap aratus and more particularly to vacuum tu es for various uses, and more especially to atype of vacuum tube for wireless signal apparatus. Vacuum tubes of the type including plates, filaments and grids are hermetically sea le and so constructed that it is practically 1mpossible to make renewals, replacements, adjustments and variations as to the enclosed plates, grids and filaments, and especlally without breaking of severing the tube glass to provide access to the enclosures. This makes it impractical to attempt'to renew, re-

- ther,

place, adjust or vary the enclosed elements in the tube. o

An object of the present inventlon 1s to provide a novel vacuum tube consisting of a tube member or bulb .combined with a mercury column, these elements being so connected that byfall of the mercury in the column, a vacuum. or partial vacuum, will be established in the vacuum chamber, and means are provided for closing the chamber mechanically above the mercury column so as to'eiectually maintain the vacuum in the vacuum member hereinafter called the vac' uum tube.

An object is to provide a vacuum apparatus in which there is combined a vacuum tube and a, mercury column, having a cell open to atmospheric pressure and into which the mercury column may recede from its standpipe when the same is `hermetically but removably attached to a contiguous portion of the vacuum tube.. An object is to provide means 'for closing communication between the vacuum tube and the mercury standpipe after the vacuum has been created, and especially an object lis to provide means manually adjustable after the establishment@ of the vacuum, substantially without inver sion or other manipulation of the mercury column.

Another object is to provide an improved filament device in the vacuum tube, and, :turan objectis to provide an improve plate and grid device. Alsoan object is to provide Jfor rthe effective removal, adjustment, alteration and replacement of the elementswithin the vacuum tube without destroying or injuring the same and without requiring the breaking of the tube wall and repairing the same, or resealing the same by fusion thereof.

An embodiment of the invention is de- 1922. Serial No. 558,631.'

a device embodying the invention.

Fig. 2 is a dmgrammatic view showing av d form of the multiple filament.

Fig. 3 is a plan view of an improved form i lof late.

ig. 4 is a side elevation of an improved form of grid. i The apparatus is shown as embodied, in one of its forms, in a vacuum, tube which ma include a bulb like bod 2 provided wit means for holding suitable grid, filament and plate devices common in wireless and other electrical apparatus. Such means I prefer to construct in the form of an annulus which here is secured to a ange like portion 2 of the vacuum tube. In the carrier Aring 3 there is mounted a removable bushing or core 4 normally sealed upon the carryingring 3 to maintain a vacuum but providing for the removal of the core 4 for' ermitting replacement, renewal, adjustment, inspection and for other purposes, as of the plate, filament and grid devices, which latter are, preferably, carried or mounted upon the inner face of the core 4, upon the outer face of which are provided the terminals or binding posts for the several plate, grid. and filament devices respectively indicated as a plate P, a grid G and a filament F. This, therefore, enables the insertion of these elements by the mounting of the core 4 upon thefastening ring or carrier 3 and upon injury or destruction of theenclosed elements, the core may be removed and changes and in spection made as desired and then this is returned in place without injury of the aparatus.- Suitable means are provided for the establishment of a vacuum in the vacuum tube 2 and means are provided for maintaining the vacuum, which enables the removal of the vacuum tube from the vacuum producing d means without destroying the vacuum in the saA a presproduce a vacuum', or partial vacuum, in the vacuum tube 2 in the well known manner of a mercury barometer. Afterthe vacuum has been established, in whatever manner this may be secured, in the tube 2, the latter is adapted to be closed as by the seating of a valve 9 upon the valve seat 5 of the tube 2. When thevacuum producing means is ofthe type here shown, including the mercury column, the valve may be closed by a device includlng a part which is exposed t be manually engaged. Such part may consist of a handle 10 on the upper end of a spindle 11 suitably supported in well 8 and having a pinion 12 engaging a gear 13 which is secured on the lower end of a vertical shaft 14 supported in the standpipe6. The upper end of the shaft 14 is provided with a coupling or socket member 15 and this is designed to be detachably coupled to the complementary end of a threaded shank 16 of the valve 9, which shank" turns in a nut 17 fastened in the tube neck 2a. Turning the handle member 10, therefore, rotates the shaft- 14 and this by engagement with .the screw shank 16 causes the Valve 9 to be pressed to its seat and effectually seal the vacuum tube 2. Thereafter this tube, for any purpose, may be removed from the vacuum roducing standpipe 6 without destroying t e vacuum in the tube.

A further'feature of my invention consists in providing means for increasing the length of life of a vacuum tube and for obviating lfrequentv renewal of the filaments and, further, for providing a'variable calEacity and to that end I provide .what might e termed a multiple filament, such, for mstance, as is illustrated in Fig. 2 in which a number of filament strands 20 each have one end connected to a common terminal 21, While veach has an 'individualterminal 22 leading, for instance, to the exterior of the mountlng 4 as above described.

Fron this it will be seen that any one of' the filament strands 20 may be thrown separately into circuit or any combinaion of the samemay be utilized, thus providing for variable capacity. By providing separate strands of filaments, one may be utilized until it becomes inoperative or destroyed and then the circuit can be thrown onto the other usable filaments as occasion may require, in this manner increasing the serviceability of the vacuum tube before necessitating dismantling and renewal.

Another object is to provide plates, grids lthan that which is in the well.

and filaments of increased effective area within a given length of grid or filament and given size of plate and to that end I have shown in Fig. 3 a plate structure in which a single strand 23 is coiled into a helix and this is arranged in a series of stretches disposed in parallel position in a common plane 1n this manner securing a large area of strand 23 within limited dimensions.

A filament and a grid of increased effective area may likewise be constructed by utilizing a strand as 24, Fig. 4, coiled in helical form and the helix thus formed may also be again coiled into helical form. It will be seen that by this construction, where space is limited, a large area of a single strand can be produced.

When they electrical grid, filament, or plate conductors are madefof helices, they may be wound upon astrand core as a bundle of wires 24a', or this core may be in the form of zhelix 24, or the combination as shown in In the erection of the vacuum lproducing means the vacuum tube is filled with the mercury, while in an upright position, and the lower end of the standpipe 6 may be temporarily sealed as .by a cap or sleeve 13a which may be formed on one side of the gear 13. By screwing the standpipe 6 down into the cap or sleeve 13%, the apertures formed in the sides of the cap by the lower end oflthe sleeve, and in this way the level of mercury in the standpipe can be maintained therein at a higher pomt When .it is desired to form the vacuum in the tube, on

reversely screwing the standpipe 6 the apertures in the sides of the capcan. be uncovered and the mercury then, which is 1n the standpipc, will tend .to falland a proach the level of the mercury in the wel This sleeve may be internally threaded with a left hand thread to engage complementary threads on the adjacent end of the standpipe 6 and by this means the latter is closed f while in the upright position of the filled tube 2. The tube is then inverted withl the standpipe adjusted to the position shown in Fig. 1 and the cap 13 is then turned off or back to the well. Atthis time the valve 9 would be open. The valve may remain open so long as the tube is connected to the standpipe 6, or may be closed as desired. v The'valve is closed when the vacuum tube is removed from the standpipe to maintain the vacuum in the tube. It will be seen that it is not necessary to remove and invert the since it may be charged by'uncovering the upper end of the tube2 by removing the filament base; in which case the gear cap 13 will bein closing position. Various modifications and changes may mercury standpipebe resorted to within the spirit of the invention as claimed.

.Vhat is claimed is:

l. A vacuum producing means including a well, a standpipe mounted to extend down into the well, a cap at thc'lower end of the standpipe and having a port (to open and close by rotating the cap relative to the standpipe, a stem. mounted in the standpipe and extending through the cap, a gear upon the cap, a second gear in mesh with the iirst gear, ra spindle extending upwardly from the second gear, a handle upon the upper end of the spindle, a coupling at the upper end ot the standpipe adapted to receive a vacuum tube,I and a socket upon the upper end or' the stem adapted'to engage and operate a'valve of a vacuum tube.

Q. A device ot the class described com-i prising an open ended container, a carrier ring mounted upon jone end of the ccntainer, a closure threaded vinto the carrier ring carrying a plate, ilament and grid which are disposed within the container, means providing a valve seat in the other end of the container, and a valve mounted upon the container adapted to seat thereon.

3..A device of the class described comprising a container adapted to have .a vacuum produced therein, said container having two openings formed therein, a carrier ring secured to the container about one of die openings, a closure threaded into the carrier ring, a filament, grid and plate carried by said closure and disposed within the container, means providing a valve seatin the other opening, an apertured nut mounted in the last named opening adjacent the valve seat, a screw threaded into said nut,

and a' valve closure carried by said screw adapted to seat upon said seat.

Ll. A device of the class described comprising a container having open ends, one of which is larger than the other, a carrier ring mounted upon the large end of the container, a closure detachaby mounted upon the carrier ring carrying an electrode disposed withinthe container, means providing a valve seat in the small end of the container, an apertured nut mounted in the small end ot'the container, a screw threaded into the nut, and a closure carried by the screw adapted to seat upon said valve seat.

5. A device for exhausting vacuum tubes comprising a container adapted to hold a liquid, a tube havingits lower end disposed within the container and its upper end extending above the top of the container, a shaft rotatably mounted within said tube, means upon the upper end of the shaft to operate a valve upon rotation of said shaft, and means for rotating said shaft.

6. A device i'or exhausting vacuum tubes comprising a container adapted to hold a liquid, a tube having its lower yend disposed within the container and its upper end eX- tending above the top of the container, a shaft rotatably mounted within said tube, means upon the upper end of the shaft to operate a valve upon rotation of said shaft, a handle rotatably mounted in the container, and gears connecting the handle to said shaft whereby the' shaft may be rotated by the handle.

In testimony whereof I have signed my name to this speciiieation.

`JOHN L. BROWN. 

